Joseph R. Biden Jr. and the Democratic National Committee had, by far, their biggest fund-raising month of the campaign in May, pulling in $80.8 million as large and small donors alike consolidated behind the presumptive Democratic nominee ahead of his fall contest with President Trump.
Mr. Biden had struggled with fund-raising throughout much of the primary season, but the pace of giving has sharply increased in recent months.
“I’m in awe of this sum of money,” Mr. Biden wrote in a note to supporters on Monday as he announced the figures. Next week, he is set to get an additional financial boost from former President Barack Obama, who will join him for a virtual grass-roots fund-raiser on June 23.
The influx of cash last month came despite a pandemic that has driven 40 million Americans from their jobs and caused unemployment rates to spike nationwide.
The May haul was more than 30 percent higher than the $60.5 million that Mr. Biden and the party had raised in April, when Mr. Trump and the Republican National Committee raised $61.7 million. Notably, May was also the first full month that Mr. Biden had an agreement to raise money in tandem with the D.N.C. through what is known as the Biden Victory Fund, which allows a single donor to give more than $620,000. Mr. Trump has been raising money in such large chunks for many months.
Mr. Trump’s campaign has not released fund-raising figures for May yet. But on Monday his campaign and R.N.C. officials highlighted that they had raised $14 million on Sunday, Mr. Trump’s 74th birthday.
“Biggest single-day ONLINE fundraising total ever,” Brad Parscale, Mr. Trump’s campaign manager, wrote on Twitter. The Trump campaign said the average online contribution was $46.
Mr. Biden’s campaign sought to highlight the role of small contributors in its growing fund-raising operation, noting that the campaign had tripled its number of online donors since February, and that more than half of the contributors last month were new to the campaign. It said its average online contribution was $30.
Mr. Biden began May with a fund-raising event held by alumni of the Obama administration that raised $1 million, and followed that with a series of high-dollar virtual fund-raisers held via Zoom.
The hosts of fund-raisers last month included Hillary Clinton; Gov. Gavin Newsom of California; David Cohen, a senior executive at Comcast who also hosted Mr. Biden’s first event the day he announced his candidacy in 2019; Senator Cory Booker of New Jersey; and Pete Buttigieg, another former 2020 rival.
Two potential running mates for Mr. Biden also headlined events in May: Senator Tammy Duckworth of Illinois and Representative Val Demings of Florida, whose event was attended by Mr. Biden’s wife, Jill Biden.
This spring, the Biden campaign named Rufus Gifford, who served as finance director on Mr. Obama’s re-election campaign, as deputy campaign manager, a decision seen as elevating the role of the finance operation inside the campaign.
Mr. Biden’s fund-raising in June also appears to have gotten off to a strong start. With protesters filling the streets to march against systemic racism, police violence and the killing of George Floyd, Mr. Biden’s campaign set records for online advertising.
In the first week of June, the campaign spent more than $1 million on Google ads and millions more on Facebook, peaking at $1.6 million in a day — roughly quadruple his previous high soon after he took control of the nominating contest on Super Tuesday.
The Biden campaign said on Monday it had added 1.5 million new supporters to its email list this month.
Thomas Kaplan contributed reporting.